Strain anchor



Nov. 19, 1968 HIKOITSU WATANABE ETAL 3,411,253

STRAIN ANCHOR Filed Oct. 28, 1965 5 Sheets-Sheet l INV NTORS J15. M w

Nov. 19, 1968 HKKOITSU WATANABE ETAL 3,411,253

STRAIN ANCHOR v Filed vOct. 28, 1965 5 Sheets-Sheet 2 lNVENTOfl mm M BY3 I" Nov- 19, 9 HIKOITSU WATANABE ETAL 3,411,253

STRAIN ANCHOR Filed Oct. 28, 1965 5 Sheets-Sheet 3 United States Patent3,411,253 STRAIN ANCHOR Hikoitsu Watanabe, -13 l-chome, Ehara-cho,Nakanoku, and Sanji Genma, 4-8 l-chome, Ehara-cho, Nakano-ku, both ofTokyo, Japan Filed Oct. 28, 1965, Ser. No. 505,560 11 Claims. (Cl.52158) ABSTRACT OF THE DISCLOSURE A strain anchor for the groundcomprising a resistance plate adapted to be inserted completely into theground in a first downward direction path. A pulling-up means isoperatively connected and projects upwardly therefrom through the groundsurface in the inserted position of the resistance plate, and a separatestabilizing plate means for being inserted into the ground and abuttingtherebelow the resistance plate with a surface thereof positionedcross-wise to the downward direction path, thereby preventing removal ofthe resistance plate upwardly along the first downward direction path.

The present invention relates to a strain anchor.

It is an object of the present invention to provide an anchor having astrong strain resistivity, and effecting embedment quite easily andbeing extremely secure in position.

It is another object of the present invention to provide a strain anchorfor the ground comprising a resistance plate adapted to be insertedcompletely into the ground in a first downward direction path. Apulling-up means is operatively connected and projects upwardlytherefrom through the ground surface in the inserted position of theresistance plate, and a separate stabilizing plate means for beinginserted into the ground and abutting therebelow the resistance platewith a surface thereof positioned cross-wise to the downward directionpath, thereby preventing removal of the resistance plate upwardly alongthe first downward direction path, is provided.

With the above and other objects in view which will become apparent inthe following detailed description, the present invention will beclearly understood in connection with the accompanying drawings, inwhich:

FIGURE 1A is a side elevational view of the anchor;

FIG. 1B is a perspective front view thereof;

FIG. 1C is a perspective rear view thereof;

FIG. 2A is a plan view of the stabilizing plate, one of the elements ofpresent invention, shown here in disassembled state;

FIG. 2B is a front view of the stabilizing plate;

FIG. 2C is a perspective front view of the stabilizing plate;

FIG. 2D is a perspective rear view of the stabilizing plate; and

FIGS. 3 through 6 illustrate the modes of operation of the invention.

The present invention relates to an extremely strong strain anchor whichis constructed so as to perfectly regulate revolving and shiftingconditions of the resistance plate with the aid of a stabilizing plateso that the resistance plate which is embedded in the ground is revolvedand shifted under such conditions that its maximum effective resistancearea faces straight against the tensile force direction in the ground bybest utilizing the resistance against the huge earth pressureencountered during use.

Referring now to the drawings, and more particularly to FIG. 1, thestrain anchor of the present invention comprises a rectangular steelresistance plate 1 in which the tip is pointed and the plate islongitudinally bent along its entire length in a suitable circular arcform, so as to facilitate driving the plate into the ground along anarcuate path. A directional plate 2 is fixed perpendicularly to thelongitudinal center line of the inner arc face of the resistanceplate 1. A reinforcing piece 4 is provided. A driving and pulling-upplate 3 is provided with a pulling-up rod 9, fitted adjacent the rearend thereof, with its other tip being affixed by means of a rivet 6 tothe longitudinal central section of the directional plate 2. Acontroller 8 is provided at the engaging part of the directional plate 2and the driving and pulling-up plate 3 thereby prevents the driving andpulling-up plate 3 from pivoting parallel to the directional plate 2 andto thus permit maintenance of a maximum spread-out condition wherein nohindrance is developed for the driving operation by the driving andpulling-up plate 3. A stabilizing late support 5 is provided at the rearpart of the resistance plate 1 which corresponds to the back side of therear end of the directional plate 2. At the rear end of the directionalplate 2 there is provided a guide plate 7 which is bent in an arc shapein such a manner that the tail-end thereof is located close to the rearend of the driving and pulling-up plate 3.

Since the guide plate 7 is the one whereby a stabilizing plate 10 (FIG.2), described later, is made to advance in a curved line, it is bent insuch a manner as to correspond with the bent face of the stabilizingplate 10. Accordingly, it is of course required to bend the face of thestabilizing plate support 5 at which the stabilizing plate 10 is fixed,so as to correspond with the bent face of the stabilizing plate 10. Thusthe correlated bent faces of the guide plate 7, the stabilizing platesupport 5 and the stabilizing plate 10 must be in perfect accord witheach other.

These elements framed as described above, compose the anchor of thepresent invention.

Referring now again to the drawings, and more particularly to FIG. 2,the stabilizing plate .10 is made of a rectangular steel plate, with itsend being pointed, and is bent in accord with the arc of the guide plate7 and is provided with bands 11 and 12 in mutually separated positionsat a properly selected portion on the longitudinal center line in theexternal arc face thereof. A reinforcing plate 13 is disposed on thelengthwise center line in the inner arc face. Elements 3 and 9constitute a pulling-up means.

It is vitally important in this case that the band 11 alone is fittedlightly so as to be easily detached by collision with other parts causedby impact at the time of drive-in.

Now the mode of operation of the present invention is set forth. First,as illustrated in FIG. 3, the rear end of the driving and pulling-upplate 3 is struck with a hammer or the like to drive the anchor bodyinto the ground, with the resistance plate 1 following along dashed line14 which is a continuation of the arc of the resist ance plate 1. Duringits path of travel the earth above the resistance plate 1 is notdisplaced except for the portions displaced by the plates 2 and 3, whichplates 2 and 3 are disposed in a vertical plane perpendicular to plate 1and which remove little earth above plate 1. Then the stabilizing plate10 is engaged with the guide plate 7 exposed above the earth surface bymeans of the bands .11 and 12 and then hit in an optional way to bedriven into the ground. The stabilizing plate 10 enters the ground alongthe arcuate path of the guide plate 7 until the band 11 reaches thedirectional plate 2 (FIG. 4) and displaces no earth above the upper faceof the plate except that displaced by the reinforcing plate 13. But theband 11 comes off easily with the impact, allowing the plate to proceedfarther on, until finally the band 12 strikes adjacent the directionalplate 2, whereat the insertion of plate 10 is completed since the band12 is solidly fixed. The stabilizing plate 10 now rests at the tail endsof the resistance plate 1 and the directional plate 2, respectively, insuch a condition that the entire effective resistance area facesstraight thereto.

Under these conditions, when a pulling-up force P is placed on thedriving and pulling-up plate 3 through the pulling-up rod 9, the forceis immediately resolved into force components A and B, as illustrated inFIG. 5, causing the resistance plate .1 to shift in the manner as shownin FIG. 6. That is, the plate 1, which would otherwise tend to passupwardly along the path 14 (FIG. 3) along which it entered the groundand along which path 14 it displaced some earth, instead would beprevented from such upward movement by the plate 10 which is orientedcross-wise to the tail or upper end of plate 1, and which plate 1 isprevented from movement in the direction of force A by the earth abovethe plate 10, which earth above plate 10 was not dislocated by theprovision of the present invention of subsequent entry of plate 10 intothe ground after the plate 1 was first inserted.

The stabilizing plate is fixed at the tail end of the resistance platein such manner that the maximum effective resistance surface of thestabilizing plate faces directly the lengthwise direction of theresistance plate, causing the resistance plate to immediately revolveand shift when a pulling force is exerted thereon, whereby the hugeanti-strain strength is instantly obtained without permitting theresistance plate to be pulled backwards along the path along which itwas inserted into the ground due to the upward tension caused by thepulling force. Thus an enormous anti-strain strength is provided and thedesired objective for an anchor is perfectly realized.

While I have disclosed one embodiment of the present invention, it is tobe understood that this embodiment is given by example only and not in alimiting sense, the scope of the present invention being determined bythe objects and the claims.

We claim:

1. A strain anchor for the ground comprising an elongated resistanceplate having a substantial surface area adapted to be insertedcompletely into the ground in the plane of its elongated direction in afirst downward direction path,

a pulling-up means operatively connected to said resistance plate andprojecting upwardly therefrom through the ground surface in saidinserted position of said resistance plate,

a single separate, stabilizing plate means having a substantial surfacearea for being inserted into the ground to a position abuttingtherebelow said resistance plate and including a surface thereofpositioned cross-wise to said first downward direction path, therebypreventing removal of said resistance plate upwardly along said firstdownward direction path, and

said stabilizing plate means for being inserted into the ground in adirection perpendicular to its surface in a second downward directionpath crossing said first downward direction path.

2. The strain anchor, as set forth in claim 1, wherein said stabilizingplate means is operatively connected to said resistance plate in saidinserted position.

3. The strain anchor, as set forth in claim 2, wherein said operativeconnection of said stabilizing plate means to said resistance plate is apivotal connection.

4. The strain anchor, as set forth in claim 2. wherein said pivotalconnection of said stabilizing plate means to said resistance plate isat the uppermost end of said resistance plate.

5. The strain anchor, as set forth in claim .1, further 5 comprising aguide plate connected to said resistance plate and projecting therefromin said inserted position upwardly to adjacent the ground surface, and

means for slidably connecting said stabilizing plate means to said guideplate adjacent the ground surface.

6. The strain anchor, as set forth in claim 5, wherein said guide plateis connected to said resistance plate cross-wise to said elongateddirection.

7. The strain anchor, as set forth in claim 6, wherein said resistanceplate is arcuately curved along its length and including a pointed endfor insertion into said ground,

said guide plate being curved and its curve constituting said seconddownward direction path,

said stabilizing plate means is curved complementary to that of saidguide plate and includes a pointed end for insertion, and

said guide plate being connected to said resistance plate at the otherend of the latter.

8. The strain anchor, as set forth in claim 7, wherein said resistanceplate is substantially rectangular,

a directional plate perpendicularly secured to the inner curved surfacealong the longitudinal center line of said resistance plate,

said pulling-up means comprises a straight elongated driving andpulling-up plate pivotally connected at one end centrally to saiddirectional plate and parallel thereto and a pulling-up rod connected tothe other end of said driving and pulling-up plate and extending throughthe ground surface in said inserted position,

said guide plate aligned substantially in the same plane as saiddirectional plate,

said stabilizing plate means substantially forming a rectangle smallerthan that of said resistance plate,

a reinforcing plate perpendicularly secured to the inner curved surfacealong the longitudinal center line of said stabilizing plate means, and

two bands connected to the other curved surface on the longitudinalcenter line of said stabilizing plate means and spaced from each otherand adapted to be slidably connected to said guide plate.

9. The strain anchor, as set forth in claim 8, wherein one of said bandsis positioned releasably adjacent said pointed end of said stabilizingplate means,

a stabilizing plate support secured longitudinally to the outer curvedsurface on the longitudinal center line of said resistance plate at saiduppermost end thereof and adjacent to said guide plate, forming acontinuation of the curve of said guide plate and abutting the outersurface of said stabilizing plate means when the latter is in theinserted position,

said inner surface of said stabilizing plate means being substantiallyperpendicular to said first downward direction path in said insertedposition, and

said longitudinal center line of said stabilizing plate means beingcross-wise to said first downward direction path.

10. The strain anchor, as set forth in claim 9, wherein said guide plateis bendably connected to said resistance plate.

11. The strain anchor, as set forth in claim 10, wherein said guideplate is curved centrally toward said driving and pulling-up plate, and

a controller plate means is secured to said directional plate adjacentsaid driving and pulling-up plate for preventing the latter frombecoming parallel to the length of said resistance plate.

(References on following page) 5 6 References Cited 1,580,605 4/1926Johnson 52--163 UNITED STATES PATENTS 1,821,125 9/1931 ThOl'll 52-163 ffHENRY c. SUTHERLAND, Primary Examiner. Burns ;t a 1. 52-163 5 R. s.VERMUT, Assistant Examiner.

Fielding 52163

